Boil the potatoes for 5 minutes in salted water. Drain and let cool.
Heat 2 tablespoons olive oil in a pan with a thick bottom and fry the onion sweet and gentle for about 10 minutes.
Meanwhile, whisk the eggs with paprika, cayenne pepper, salt, dried parsley, pepper and grated garlic.
Stir the balsamic vinegar and bTagatesse through the onion and cook for 2 minutes until the Tagatesse has dissolved. Remove the onions from the pan. Add the last tablespoon of olive oil in the pan and place here the slices of potato. Spread the onions on top and pour the egg mixture over it.
You can bake the frittata over low heat for 20 minutes in a pan, but you can also bake it in a preheated oven for about 15 minutes at 175°C.